长期菌渣化肥配施对稻田土壤酶活性的影响及交互效应

  目的  探讨长期尺度上不同比例菌渣化肥配施对水稻Oryza sativa生育时期土壤酶活性的影响。  方法  在水稻田间长期定位试验条件下，设置化肥水平为常规施肥量的0%(C₀)、50%(C₅₀)、100%(C₁₀₀)，菌渣相对用量0%(F₀)、50%(F₅₀)、100%(F₁₀₀)各3个水平，共9个处理，分析了水稻主要生育时期各处理土壤中过氧化氢酶、蔗糖酶、脲酶活性变化，以及菌渣化肥配施对土壤酶活性的交互效应。  结果  土壤酶活性随水稻生育时期的变化呈现出明显规律性，过氧化氢酶、蔗糖酶、脲酶活性分别为3.01~10.20 mL·g?1、0.20~2.04 mg·g?1、0.54~4.80 mg·g?1；在水稻不同生育期，各处理间土壤过氧化氢酶、蔗糖酶和脲酶活性具有显著差异(P＜0.05)。菌渣化肥配施对水稻移栽前期的土壤脲酶活性提高有促进作用，且增强了水稻灌浆期和收获期的土壤过氧化氢酶和蔗糖酶活性，其中过氧化氢酶活性和脲酶活性在C₁₀₀F₅₀处理最高，而蔗糖酶活性在C₅₀F₁₀₀处理最高。通径分析表明:有效磷、碱解氮和全氮分别对过氧化氢酶、蔗糖酶和脲酶影响最大，通径系数分别为0.69、1.80和0.69。菌渣化肥配施主要通过提高碱解氮质量分数促进土壤酶活性。交互性分析表明:菌渣化肥配施效应高于化肥和菌渣单施，并且对土壤过氧化氢酶、蔗糖酶和脲酶活性均有显著影响(P＜0.05)。  结论  菌渣化肥配施能够显著提高土壤过氧化氢酶、蔗糖酶、脲酶活性，并且随施用量增加呈现先增高后降低的趋势；本试验条件下，C₁₀₀F₅₀处理是提高土壤酶活性和促进碳氮循环的最佳选择。图1表4参38

Effects of long-term combined application of fungus residue and chemical fertilizer on soil enzyme activities in paddy field

  Objective  The purpose of this study is to explore the effects of different proportions of fungus residue and chemical fertilizer on soil enzyme activities during the rice growth period over a long-term scale.  Method  A long-term location experiment in paddy field was carried out in which the fertilizer levels were set as 0% (C₀), 50% (C₅₀) and 100% (C₁₀₀) of conventional fertilization amount, and the relative amount of edible fungus residue was set as 0% (F₀), 50% (F₅₀) and 100% (F₁₀₀), respectively. There were 9 treatments in total. The changes of catalase, sucrase and urease activities in different treatments at the main growth stages of rice and the interaction effect of fungus residue and chemical fertilizer on soil enzyme activities were analyzed.  Result  The soil enzyme activities showed obvious regularity with the change of rice growth period. The catalase, sucrase, and urease activities were 3.01?10.20 mL·g?1, 0.20?2.04 mg·g?1, and 0.54?4.80 mg·g?1 respectively. There were significant differences (P＜0.05) in soil catalase, sucrase and urease among the treatments in different growth stages of rice. The results showed that the combined application of fungus residue and chemical fertilizer promoted the soil urease activity in the early stage of rice transplanting, and enhanced the activities of catalase and sucrase in the filling stage and harvest stage. The activities of catalase and urease were the highest in C₁₀₀F₅₀ treatment, while the sucrase activity was the highest in C₅₀F₁₀₀ treatment. Path analysis showed that available phosphorus, alkali hydrolyzed nitrogen and total nitrogen had the greatest impact on catalase, sucrase and urease respectively, with path coefficients of 0.69, 1.80, 0.69 respectively. The combined application of fungus residue and chemical fertilizer promoted soil enzyme activity mainly by increasing the mass fraction of alkali hydrolyzed nitrogen. Interaction analysis showed that the effect of combined application of fungus residue and chemical fertilizer was higher than that of chemical fertilizer and fungal residue alone, and the activities of catalase, sucrase and urease in soil were significantly affected (P＜0.05).  Conclusion  The combined application of fungus residue and chemical fertilizer can significantly increase the activities of soil catalase, sucrase and urease, but with the increase of application amount, the activity of soil catalase, sucrase and urease increases first and then decreases. C₁₀₀F₅₀ treatment is the optimal choice to improve soil enzyme activity and promote carbon and nitrogen cycle under the experimental condition. Ch, 1 fig. 4 tab. 38 ref.]